JP3622394B2

JP3622394B2 - Noble gas discharge lamp for document illumination

Info

Publication number: JP3622394B2
Application number: JP00322397A
Authority: JP
Inventors: 敏田村
Original assignee: Ushio Denki KK
Current assignee: Ushio Denki KK
Priority date: 1997-01-10
Filing date: 1997-01-10
Publication date: 2005-02-23
Anticipated expiration: 2017-01-10
Also published as: JPH10199488A

Description

【０００１】
【発明の属する技術分野】
この発明は原稿照明用希ガス放電灯に関し、特にガラスバルブの外周面に一対の帯状の外部電極を配置し、外部電極間に第１，第２の開口部を有する希ガス放電灯において、第１の開口部の前面照度の改良に関する。
【０００２】
【従来の技術】
従来のこの種希ガス放電灯は、例えば図１３に示すように構成されている。同図において、Ａは例えばガラスバルブよりなる外囲器であって、その内面には希土類蛍光体，ハロリン酸塩蛍光体などの蛍光体よりなる発光層Ｂが形成されているが、その一部には発光層Ｂを形成しないアパ−チャ部Ｂａが形成されている。そして、外囲器Ａの内部空間には例えば水銀などの金属蒸気を含まないキセノンガスなどを主成分とする希ガスが所定量封入されている。一方、外囲器Ａの外周面には、例えばアルミニウムなどの不透光性の金属部材よりなる帯状の一対の外部電極Ｃ，Ｄが互いに対向し、かつ第１，第２の開口部ＰＡ，ＰＢが形成されるように貼着されており、その外周面は熱収縮性樹脂よりなる保護チュ−ブＥにて被覆・保護されている。
【０００３】
この希ガス放電灯は、図示しない端子を介して外部電極Ｃ，Ｄに高周波高電圧（例えば２５ＫＨｚで２５００Ｖｏ−ｐ）を印加することによりキセノンガスの放電が生じ、キセノンガスの励起線によって発光層Ｂが励起されて発光するものであり、光はアパ−チャ部Ｂａから外部電極Ｃ，Ｄの端部Ｃａ，Ｄａ間の第１の開口部ＰＡを経由して外部に放出される。特に、この希ガス放電灯には水銀が用いられていないために、点灯後における光量の立ち上がりが急峻であり、点灯と同時に光量がほぼ１００％近くにまで達するという特徴を有している。このために、ファクシミリ，イメ−ジスキャナ，複写機などのＯＡ機器の原稿読取用の光源として好適するものである。
【０００４】
【発明が解決しようとする課題】
ところで、このような希ガス放電灯を原稿照射装置に適用した場合、原稿の読み取り精度は主として原稿面の照度（第１の開口部ＰＡの中央部分の前面照度）及び原稿の送り速度に大きく影響される。例えば原稿面の照度が一定の場合には、原稿の送り速度が遅いほど読み取り精度は向上し、原稿の送り速度が高速化されるほど読み取り精度は低くなる。又、原稿の送り速度が一定の場合には、原稿面の照度が高いほど読み取り精度は向上し、原稿面の照度が低いほど読み取り精度は低くなるものである。従って、近時、ＯＡ機器が、処理能力を高め、事務処理の効率化を図るために、原稿の送り速度を高速化する傾向にあることから、希ガス放電灯から放出される光量は一層に増加することが望まれている。
【０００５】
この希ガス放電灯において、発光層Ｂから放射される光は、アパ−チャ部Ｂａ，第１の開口部ＰＡを介して外部に放出されるものと、第２の開口部ＰＢから外部に放出されるものとがあり、原稿照射装置の読み取りに利用される光は前者のアパ−チャ部Ｂａ，第１の開口部ＰＡを介して外部に放出されるものだけである。例えば外径が６ｍｍ，長さが２８０ｍｍの外囲器Ａの外周面に外部電極Ｃ，Ｄを配置してなる希ガス放電灯では、第１の開口部ＰＡの中央部分の前面８ｍｍにおける照度はほぼ１００００Ｌｘが得られる。
【０００６】
しかしながら、上述のように、希ガス放電灯の第１の開口部ＰＡの前面照度をさらに高める必要がある場合には、例えば外囲器Ａの外径を大きくしたり、或いは管入力（外部電極間に供給する電力）を増加したりする方法が採用されるものの、それぞれに次のような問題を有している。
【０００７】
即ち、前者の方法では、ＯＡ機器の小形化に伴い、希ガス放電灯の収納空間も狭くなっていることから、組み込みに困難が予想される。又、後者の方法では、管入力を増加させると、第１の開口部ＰＡの前面照度は増加するものの、第２の開口部ＰＢから放出される光量も増加することになる。従って、管入力を増加させる割には第１の開口部ＰＡから放出される光量の増加割合が少ないのみならず、点灯装置が大形化してしまうという問題がある。
【０００８】
それ故に、本発明の目的は、簡単な構成によって第２の開口部から逸散される光を有効に利用し、第１の開口部の前面照度を高めることのできる希ガス放電灯を提供することにある。
【０００９】
【課題を解決するための手段】
従って、本発明は、上述の目的を達成するために、内面に発光層を有する直管状の外囲器と、外囲器の全長とほぼ同程度の長さを有する透光性シートの一方の面に金属部材よりなる帯状の一対の外部電極を、第１，第２の開口部が形成されるように、互いに離隔して配置してなるシート構体とを具備し、前記シート構体を外囲器の外周面に、外囲器と透光性シートとの間に外部電極が位置するように巻回すると共に、当該外囲器の外周面上の外部電極間の第２の開口部に対応する部分に光反射性を有し絶縁性を有する反射部材を配置し、第１の開口部から光を放出するように構成したことを特徴とする。
【００１０】
又、本発明の第２の発明は、内面に発光層を有する直管状の外囲器と、外囲器の全長とほぼ同程度の長さを有する透光性シートの一方の面に金属部材よりなる帯状の一対の外部電極を、第１，第２の開口部が形成されるように、互いに離隔して配置し、かつ透光性シートの一方の面に粘着ないし接着機能を有する接着層を形成してなるシート構体とを具備し、前記シート構体を外囲器の外周面に、外囲器と透光性シートとの間に外部電極が位置するように巻回し接着すると共に、当該外囲器の外周面上の外部電極間の第２の開口部に対応する部分に光反射性を有し絶縁性を有する反射部材を配置し、第１の開口部から光を放出するように構成したことを特徴とする。
【００１１】
さらに、本発明の第３の発明は、前記反射部材を、第２の開口部に対応する透光性シート部分に一体化したことを特徴とし、さらに、第４の発明は、前記外部電極間の第１の開口部に対応する外囲器の内面部分に発光層の形成されないアパーチャ部を形成したことを特徴とする。
【００１２】
【発明の実施の形態】
次に、本発明の第１の実施例について図１〜図４を参照して説明する。同図において、１は例えばガラスバルブにて密閉状に構成された直管状の外囲器であって、その内面には希土類蛍光体，ハロリン酸塩蛍光体などの蛍光体よりなる発光層２が形成されているが、その一部には発光層２の形成されないアパ−チャ部２ａが形成されている。この外囲器１はガラスバルブの端部にディスク状の封着ガラス１ａ，１ｂを封着して構成されているが、例えばガラスバルブを加熱しながら縮径加工し溶断して構成することもできる。そして、この外囲器１の密閉空間には水銀などの金属蒸気を含まない例えばキセノン（Ｘｅ），クリプトン（Ｋｒ），ネオン（Ｎｅ），ヘリウム（Ｈｅ）などの希ガスが単一又は混合して所定量封入されているが、キセノンを主成分とする希ガスを例えば２０〜１１０Ｔｏｒｒの圧力で封入することが望ましい。
【００１３】
この外囲器１の外周面にはシ−ト構体３が密着するように巻回されている。このシ−ト構体３は、例えば外囲器１の全長とほぼ同程度の長さを有し、かつ厚さが２０〜１００μｍの範囲に設定された絶縁性の透光性シ−ト４と、この透光性シ−ト４の一方の面に、後述する第１，第２の開口部（８Ａ，８Ｂ）が形成されるように、互いに所定の間隔だけ離隔配置して接着された不透光性の金属部材よりなる帯状の一対の外部電極５，６と、この外部電極５，６の端部から導出された端子５１，６１と、外部電極５，６間に形成される後述の第２の開口部（８Ｂ）に対応する部分に配置された光反射性を有し、かつ絶縁性に優れた反射部材７と、透光性シ−ト４，外部電極，反射部材７の共通する一方の面に付与された粘着ないし接着機能を有する接着層９とから構成されている。
【００１４】
このシ−ト構体３において、透光性シ−ト４は、例えばポリエチレンテレフタレ−ト（ＰＥＴ）樹脂が好適するが、透光性，電気絶縁性に優れておればポリエステル樹脂，弗素樹脂（テフロン：登録商標）など他の樹脂も利用できる。又、外部電極５，６は、例えば光反射性を有するアルミニウム箔が好適するが、導電性に優れており、かつ不透光性であれば、銅，銀，ニッケルなどのように他の金属部材も利用できる。特に、外部電極５，６がアルミニウム箔にて構成されている場合、その肉厚はアルミニウム箔が硬質の場合には１０〜５０μｍ、アルミニウム箔が軟質の場合には３０〜１００μｍの範囲に設定することが望ましい。尚、この外部電極５，６の端部には端子５１，６１が導電性接着剤，かしめ，溶着などによって電気的機械的に接続されている。又、反射部材７は、例えば酸化チタン（ＴｉＯ_２），酸化マグネシウム（ＭｇＯ）などのように反射性を有する粉体、絶縁性シ−トに酸化チタン，酸化マグネシウムなどの反射材料を被着したもの、発泡ＰＥＴなどにて構成されており、第２の開口部（８Ｂ）に対応する透光性シ−ト部分に吹き付け，塗布などにより被着したり、或いは帯状のものを配置して接着されている。さらに、接着層９としてはシリコ−ン系接着剤が好適するが、アクリル系接着剤，エポキシ系接着剤なども使用可能である。この接着層９の厚みは、例えば２０〜４０μｍ程度が望ましいが、この範囲外に設定することも可能である。
【００１５】
上述のシ−ト構体３は外囲器１の外周面に、外部電極５，６が外囲器１と透光性シ−ト４との間に位置するように装着されており、後述の第２の開口部（８Ｂ）において、透光性シ−ト４の一方の端部４ａに他方の端部４ｂを重ね合わせて接着した上で超音波溶着，熱圧着などにより溶着されている。この溶着部は重ね合わせ部分の長手方向に沿って連続的ないし部分的に形成されているが、単に接着するだけで、溶着を省略することもできる。特に、シ−ト構体３の外囲器１への装着状態において、外部電極５，６の一端５ａ，６ａの間には第１の開口部８Ａが、外部電極５，６の他端５ｂ，６ｂの間には第２の開口部８Ｂがそれぞれ形成されており、その上、第２の開口部８Ｂには反射部材７が配置されている。発光層２からの光は、アパ−チャ部２ａを介して第１の開口部８Ａのみから外部に放出される。尚、第１，第２の開口部８Ａ，８Ｂの開口角θ_１，θ_２は、θ_１＞θ_２の関係に設定することが望ましいが、用途によっては同一ないし逆の関係に設定することもできる。
【００１６】
この希ガス放電灯を製造するに先立って、シ−ト構体３を含むシ−ト組立体３Ａが準備される。このシ−ト組立体３Ａは例えば図５〜図６に示すように組み立てられる。まず、図５（ａ）に示すように、例えば一方の面に離型機能を有する長尺状のセパレ−タ３Ｓを図示しない組立ステ−ジに載置すると共に、その一方の面に例えばセパレ−タ３Ｓより幅が狭く、一方の面に接着層を有する長尺状の金属部材（例えばアルミニウム箔）よりなる導電性シ−ト５Ｓを順に重ね合わせて接着する。尚、セパレ−タ３Ｓは、例えば厚さが７０μｍ程度のＰＥＴ樹脂が好適するが、材質，厚さは適宜に変更できる。特に、重ね合わせはセパレ−タ３Ｓと導電性シ−ト５Ｓとを別々のロ−ルから連続的に供給しながらロ−ラなどを利用して重ね合わせることが望ましい。そして、図示しないカッタ−によって導電性シ−ト５Ｓに、対をなす帯状の外部電極５，６が形成されるように切離部５Ｓａを順次に形成する。尚、この切離部５Ｓａは導電性シ−ト５Ｓのみが切断されるだけで、セパレ−タ３Ｓには切れ目が生じないように配慮されている。そして、外部電極として不要な部分５Ｓｂ，５Ｓｃをセパレ−タ３Ｓから、切離部５Ｓａを介して順次に分離（剥離）すると、同図（ｂ）に示すように、セパレ−タ３Ｓには対をなす外部電極５，６が所定の間隔で順に配列される。
【００１７】
次に、図６（ａ）に示すように、外部電極５に隣接するセパレ−タ３Ｓ部分に、一方の面に接着層を有する帯状の反射部材７を配置し接着する。尚、反射部材７は、外部電極５，６の形成方法と同様の方法で配置することもできる。次に、外部電極５，６の端部に端子５１，６１の一端を順次に重ね合わせ、例えば図示しない導電性接着剤などにて電気的機械的に接続する。尚、導電性接着剤としては、例えばニッケル粉末を含むアクリル系の導電性接着剤が好適するが、ニッケル以外の金属粉末を含むアクリル系ないしそれ以外の樹脂母体を使用するものでもよい。次いで、同図（ｂ）に示すように、外部電極５，６及び反射部材７の全長より幅が広く、一方の面に接着層９を有する長尺状の透光性シ−ト（例えばＰＥＴ樹脂）４Ｓをセパレ−タ３Ｓの一方の面に、外部電極５，６及び反射部材７が完全に被覆されるように順に重ね合わせて接着する。尚、この透光性シ−ト４Ｓは予めロ−ルに巻回しておき、連続的に供給してセパレ−タ３Ｓに重ね合わせることもできる。次に、図示しないカッタ−によって透光性シ−ト４Ｓに一定の間隔（一対の外部電極間）で切離部４Ｓｃを形成する。尚、この切離部４Ｓｃは透光性シ−ト４Ｓのみが切断されるだけで、セパレ−タ３Ｓには切れ目が生じないように配慮されている。そして、セパレ−タ３Ｓに例えばスポンジなどのように柔軟性ないし弾力性を有し、かつ透光性シ−ト４Ｓより幅の狭い長尺状のスペ−サ（３Ｍ）を重ね合わせて図示しないロ−ルに巻回することにより、シ−ト組立体３Ａが組み立てられる。尚、スペ−サ３Ｍは、巻回した時にシ−ト組立体３Ａが竹の子状（幅方向の両端の巻回径が異なる状態）になる場合に使用されるが、特に、シ−ト組立体３Ａを巻回した際に幅方向の全体に亘ってほぼ同一径に巻回され、形態が崩れない場合には省略することもできる。
【００１８】
このように構成されたシ−ト組立体３Ａを用いて希ガス放電灯は、例えば図７〜図９に示すように製造される。尚、この製造装置は、例えばシ−ト組立体３Ａからシ−ト構体３を分離する分離装置１００、分離されたシ−ト構体３を受け取って一定の方向に移送する移送装置２００、移送装置２００から供給されたシ−ト構体３を外囲器１の外周面に巻回する巻回装置３００などから構成されている。
【００１９】
まず、図７〜図８に示すように、シ−ト組立体３Ａは分離装置１００のロ−ル１０１に配設される。そして、スペ−サ３Ｍはロ−ル１０２に巻き取られるように、シ−ト組立体３Ａはバッファ部１０３を介してスクレ−パ１０４に移送されるようにセットされる。特に、スクレ−パ１０４には例えば１０°程度の鋭角な折り返し部が形成されており、セパレ−タ３Ｓはこの折り返し部に沿って一定のテンションを付与されてロ−ル１０５に巻き取られる。シ−ト組立体３Ａが図示矢印方向に送られ、それのシ−ト構体３がスクレ−パ１０４の下側に位置すると、その下側には移送装置２００の分離ステ−ジ２０１が配置されると共に、ステ−ジ２０１がシ−ト構体３に近接ないし密着して真空吸着される。そして、ステ−ジ２０１はシ−ト組立体３Ａの移動にほぼ同期して図示矢印方向に移動する。尚、ステ−ジ２０１はスライダ−２０２に固定されており、レ−ル２０３に沿って移動自在に構成されている。セパレ−タ３Ｓがスクレ−パ１０４の先端部１０４ａにて鋭角に折り返されると、同部分にてシ−ト構体３が扱かれ、セパレ−タ３Ｓから分離され始める。やがて、セパレ−タ３Ｓとステ−ジ２０１の移動に関連してシ−ト構体３は完全に分離され、図示点線のようにステ−ジ２０１に移されて所定位置まで移送される。尚、シ−ト構体における透光性シ−ト４Ｓには切離部４Ｓｃが適宜の間隔で形成されているために、スクレ−パ１０４の先端部１０４ａでの扱きによって確実に分離される。この分離されたシ−ト構体３が巻回装置３００に供給されると、ステ−ジ２０１は再び図８の実線位置に復帰する。尚、ステ−ジ２０１の真空吸着機構は省略することも可能である。
【００２０】
次に、図９に示すように、巻回装置３００のステ−ジ３０１に載置されたシ−ト構体３はステ−ジ３０１に、例えば真空吸着された上で、図示しないＸ，Ｙ軸方向の位置調整装置（Ｘ−Ｙテ−ブル）によって所定位置に調整される。そして、外囲器１がシ−ト構体３における反射部材７の端部（透光性シ−ト４の一端４ａ）に、それの長手方向が反射部材７（外部電極５，６）の長手方向に沿うように（平行となるように）供給・配置される。この状態で、従動的に回転し、かつ上下動可能な一対のロ−ラ３０２，３０２を外囲器１の上部に弾力的に押し付けるように位置させる。この状態において、ステ−ジ３０１を矢印方向Ｍに図示しない駆動機構によって移動させる。すると、外囲器１はロ−ラ３０２，３０２に押さえ付けられた状態で反時計方向に回転すると共に、ロ−ラ３０２，３０２も外囲器１の回転に応じて従動回転する。これによって、外囲器１の外周面の一部には反射部材７（透光性シ−ト４の一端４ａ）が密着状態で接着される。その後、ステ−ジ３０１を矢印方向Ｎに移動させると、外囲器１はロ−ラ３０２，３０２に弾力的に押さえ付けられた状態で時計方向に回転すると共に、ロ−ラ３０２，３０２も外囲器１の回転に応じて従動回転する。この際に、シ−ト構体３の透光性シ−ト４は、既に外囲器１に接着された一端４ａを起点として、外囲器１の回転に応じて外周面に巻回され始める。そして、外囲器１が例えば３９０°程度回転（ほぼ１回転）すると、外囲器１の外周面には、図１に示すように、透光性シ−ト４が巻回される上、一端４ａに他端４ｂが重ね合わされ、接着層９によって接着される。尚、外部電極５，６及び反射部材７は接着層９を介して外囲器１の外周面に接着される。又、ステ−ジ３０１の真空吸着力は外囲器１の回転による透光性シ−ト４の外囲器１への巻回・接着によって容易に離脱する程度に設定すれば、組み立て工程の途中で吸着停止（開放），吸着力の調整などを省略できる。
【００２１】
この実施例によれば、外部電極５，６の端部５ｂ，６ｂ間に形成される第２の開口部８Ｂに反射部材７が配置されているために、発光層２から放射された光は外部電極５，６及び反射部材７にて反射され、高密度化されてアパ−チャ部２ａを介して第１の開口部８Ａから外部に放出される。従って、第１の開口部８Ａの前面照度を大幅に高めることができる。
【００２２】
特に、第２の開口部８Ｂには反射部材７が配置されているために、第２の開口部８Ｂから光が外部に放出されることはなくなる。このために、第２の開口部８Ｂから放出される光が第１の開口部８Ａに集約されることになり、第１の開口部８Ａからの光量が増加し、原稿照射装置に適用した場合、原稿面照度を一層に高めることができ、原稿の送り速度が高速化されても、原稿の読み取り精度を向上させることができる。
【００２３】
又、反射部材７はシ−ト構体３の製造時に第２の開口部８Ｂに対応する透光性シ−ト部分に配置されるために、作業能率を高め、量産性を改善することができる。
【００２４】
図１０は本発明の第２の実施例を示すものであって、基本的な構成は図１〜図４に示す希ガス放電灯と同じである。異なる点は、第１の開口部８Ａに対応するアパ−チャ部２ａの開口角θ_３を第１の開口部８Ａの開口角θ_１より大きく設定し、かつ第１の開口部８Ａに発光層２が食み出さないようにしたことと、シ−ト構体３の外囲器１への巻回・密着状態において、透光性シ−ト４の端部４ｂの主たる重ね合わせ部分を外部電極５の外面側に設定し、この部分を超音波溶着したことである。尚、この重ね合わせ・溶着部分は外部電極６の外面側とすることもできる。尚、このアパ−チャ部２ａの開口角θ_３は、例えば７０〜１１０度の範囲に設定されているが、用途，目的などに応じて適宜に変更できる。
【００２５】
この実施例によれば、発光層２から放射された光は外囲器内において高密度化されてアパ−チャ部２ａから第１の開口部８Ａを経て外部に放出されるために、原稿照射装置に適用した場合、原稿面の照度を高めることができ、原稿の読み取り精度を向上できる。
【００２６】
特に、外部電極５，６の外囲器側の面に光反射性を付与すれば、反射部材７の光反射性と相俟って第１の開口部８Ａの前面照度を高めることができ、原稿の読み取り精度も改善できる。
【００２７】
又、アパ−チャ部２ａの開口角θ_３は第１の開口部８Ａの開口角θ_１より大きく設定され、かつ第１の開口部８Ａには発光層２が食み出さないように構成されているために、製造時に、アパ−チャ部２ａに対する外部電極５，６の位置関係が少々ずれても、光軸の変動を実用上支障の生じない範囲に止めることができる。従って、ＯＡ機器への組み込みが容易になる。
【００２８】
さらには、透光性シ−ト４の重ね合わせ部分の超音波溶着は外部電極５の外面側において行なわれるために、外囲器内面の発光層２に作用する超音波振動が緩和される。従って、第１の実施例に比べると、発光層２の外囲器内面からの剥離を大幅に抑制でき、光出力の改善が可能となる。
【００２９】
図１１は本発明の第３の実施例を示すものであって、基本的な構成は図１に示す希ガス放電灯と同じである。異なる点は、外囲器１の外周面に帯状の一対の外部電極５，６を対向するように貼着すると共に、外部電極５，６の第２の開口部８Ｂに対応する外囲器１の外周面に帯状の反射部材７を貼着し、かつ外囲器１の外周面に絶縁部材、例えばＰＥＴ樹脂などの熱収縮性樹脂よりなる保護チュ−ブ１０を被せたことである。尚、この保護チュ−ブ１０は外囲器１に装着した後、例えば１５０〜２００°Ｃ程度に加熱し、収縮させることによりシ−ト構体３に密着される。尚、この保護チュ−ブ１０は、第１，第２の実施例におけるシ−ト構体３に被せることもできる。この場合には、希ガス放電灯の適用部所における環境条件が厳しい，安全基準が高いなどの適用条件が厳しくても、より高品位の製品を提供できる。
【００３０】
この実施例によれば、上述の各実施例と同様に、第１の開口部８Ａの前面照度を有効に高めることができる上に、上述の実施例のように、透光性シ−ト４の端部４ａ，４ｂを重ね合わせる必要がないために、使用中に重ね合わせ部分が剥がれるという不都合を皆無にできる。
【００３１】
特に、保護チュ−ブ１０を外囲器１の外周面に装着するにに先立って、予め、外囲器１の外周面にシリコ−ンワニスなどの絶縁被膜を形成しておけば、外部電極間の絶縁性を改善でき、沿面放電の発生も抑制できる。
【００３２】
図１２は本発明の第４の実施例を示すものであって、基本的な構成は図１１に示す希ガス放電灯と同じである。異なる点は、帯状の反射部材７の両端部分を延在して外部電極５，６の端部５ｂ，６ｂに重ね合わせたことである。この構成によれば、第２の開口部８Ｂにおいて、外部電極５，６の端部５ｂ，６ｂと反射部材７との間に隙間が形成されないために、同開口部分（８Ｂ）での光反射性をさらに高めることが可能となる。
【００３３】
尚、本発明は、何ら上記実施例にのみ制約されることなく、例えば第２の開口部に対応する部分への光反射性の付与は帯状の反射部材を配置したり、反射材料を塗布・吹き付けしたりする他、外囲器自身に反射材料を直接的に被着したり、絶縁部材に反射性をもたせることもできる。又、外部電極は外囲器のほぼ全長に配置されているが、この「ほぼ全長」の意味は外囲器の全長の２０％減程度までを含むものである。
【００３４】
【実施例】
次に、第１の実験例について説明する。外径が８ｍｍ，長さが３００ｍｍの鉛ガラスよりなる外囲器に図３〜図４に示すシ−ト構体を巻回・密着させる。このシ−ト構体における外部電極には肉厚が７０μｍ，巾が８ｍｍの帯状のアルミニウムを用い、第２の開口部（幅は３ｍｍ）に対応する透光性シ−ト部分に、東レ株式会社より発泡ＰＥＴとして販売されているＥ６０Ｌ（反射部材）を帯状に加工して貼着し、かつ透光性シ−トの全面には厚さが３５μｍの接着層が形成されている。
【００３５】
この希ガス放電灯の外部電極に２５ＫＨｚ，２５００Ｖｏ−ｐの高周波高電圧を印加し、第１の開口部の中央部の前面８ｍｍ地点の照度を測定したところ、同一サイズで発泡ＰＥＴが貼着されていない従来の希ガス放電灯に比較して、照度が２８％増加した。
【００３６】
次に、第２の実験例について説明する。外径が８ｍｍ，長さが３００ｍｍの鉛ガラスよりなる外囲器に図３〜図４に示すシ−ト構体を巻回・密着させる。このシ−ト構体における外部電極には肉厚が６０μｍ，巾が８ｍｍの帯状のアルミニを用い、第２の開口部（幅は３ｍｍ）に対応する透光性シ−ト部分に、厚さがほぼ４０μｍの酸化マグネシウムの反射被膜を形成し、かつ透光性シ−トの全面には厚さが３５μｍの接着層が形成されている。
【００３７】
この希ガス放電灯の外部電極に２５ＫＨｚ，２５００Ｖｏ−ｐの高周波高電圧を印加し、第１の開口部の中央部の前面８ｍｍ地点の照度を測定したところ、同一サイズで酸化マグネシウム被膜が形成されていない従来の希ガス放電灯に比較して、照度が３５％増加した。
【００３８】
【発明の効果】
以上のように、本発明によれば、外部電極の端部間に形成される第２の開口部に対応する部分には光反射性が付与されているために、発光層から放射された光は第２の開口部から外部に放出されることなく、殆んどすべてが第１の開口部に集約される。従って、第１の開口部から放出される光量を増加でき、その前面照度を効果的に高めることができる。
【００３９】
特に、発光層に、発光層の形成されないアパ−チャ部を形成すれば、発光層から放射された光が外囲器内面で高密度化され、アパ−チャ部を介して第１の開口部から外部に放出されるために、第１の開口部の前面照度をさらに高めることができる。
【００４０】
そして、この原稿照明用希ガス放電灯を原稿照射装置に適用した場合には、原稿面照度を有効に高めることができるために、仮に原稿の送り速度が高速化されても、原稿の読み取り精度を向上させることができる。
【図面の簡単な説明】
【図１】本発明の第１の実施例を示す縦断面図。
【図２】図１のＸ−Ｘ断面図。
【図３】本発明にかかるシ−ト構体の展開図。
【図４】図３のＹ−Ｙ断面図。
【図５】本発明にかかるシ−ト組立体の製造方法を説明するための図であって、同図（ａ）はセパレ−タに導電性シ−トを重ね合わせた状態を示す平面図、同図（ｂ）は導電性シ−トの不要部分を除去して外部電極を形成した状態を示す平面図。
【図６】本発明にかかるシ−ト組立体の製造方法を説明するための図であって、同図（ａ）は反射部材を配置すると共に、外部電極に端子を接続した状態を示す平面図、同図（ｂ）はセパレ−タに透光性シ−トを重ね合わせた状態を示す平面図。
【図７】本発明にかかる製造装置の概略側面図。
【図８】図７に示す製造装置の要部拡大断面図。
【図９】本発明にかかるシ−ト構体の外囲器への巻回方法を説明するための断面図。
【図１０】本発明の第２の実施例を示す縦断面図。
【図１１】本発明の第３の実施例を示す縦断面図。
【図１２】本発明の第４の実施例を示す縦断面図。
【図１３】従来例の縦断面図。
【符号の説明】
１外囲器
２発光層
２ａアパ−チャ部
３Ａシ−ト組立体
３Ｓ長尺状のセパレ−タ
３シ−ト構体
４Ｓ長尺状の透光性シ−ト
４透光性シ−ト
４ａ，４ｂ端部
４Ｓｃ切離部
５Ｓ長尺状の導電性シ−ト
５，６外部電極
５１，６１端子
７反射部材
８Ａ第１の開口部
８Ｂ第２の開口部
９接着層
１０保護チュ−ブ（絶縁部材）
１００分離装置
１０４スクレ−パ
２００移送装置
２０１，３０１ステ−ジ
３００巻回装置
３０２ロ−ラ[0001]
BACKGROUND OF THE INVENTION
This invention For document illumination In particular, in a rare gas discharge lamp in which a pair of strip-shaped external electrodes are disposed on the outer peripheral surface of a glass bulb and the first and second openings are provided between the external electrodes, the front surface of the first opening is provided. It relates to the improvement of illuminance.
[0002]
[Prior art]
This conventional rare gas discharge lamp is configured, for example, as shown in FIG. In the figure, A is an envelope made of, for example, a glass bulb, and a light emitting layer B made of a phosphor such as a rare earth phosphor or a halophosphate phosphor is formed on the inner surface thereof, but a part thereof An aperture portion Ba is formed in which the light emitting layer B is not formed. In the inner space of the envelope A, a predetermined amount of a rare gas containing, for example, xenon gas that does not contain metal vapor such as mercury as a main component is enclosed. On the other hand, on the outer peripheral surface of the envelope A, for example, a pair of strip-like external electrodes C and D made of a light-impermeable metal member such as aluminum are opposed to each other, and the first and second openings PA, The PB is stuck so as to be formed, and the outer peripheral surface thereof is covered and protected by a protective tube E made of a heat-shrinkable resin.
[0003]
In this rare gas discharge lamp, a high-frequency high voltage (for example, 2500 Vo-p at 25 KHz) is applied to the external electrodes C and D through terminals not shown in the drawing, and a discharge of xenon gas occurs. B is excited to emit light, and light is emitted to the outside from the aperture portion Ba via the first opening PA between the end portions Ca and Da of the external electrodes C and D. In particular, since no mercury is used in this rare gas discharge lamp, the amount of light rising after lighting is steep, and the amount of light reaches almost 100% simultaneously with lighting. For this reason, it is suitable as a light source for reading originals in office automation equipment such as a facsimile, an image scanner, and a copying machine.
[0004]
[Problems to be solved by the invention]
By the way, when such a rare gas discharge lamp is applied to a document irradiating device, the document reading accuracy largely affects the illuminance of the document surface (front surface illuminance at the central portion of the first opening PA) and the document feed speed. Is done. For example, when the illuminance on the document surface is constant, the reading accuracy improves as the document feeding speed is slow, and the reading accuracy decreases as the document feeding speed increases. When the document feed speed is constant, the reading accuracy improves as the illuminance on the document surface increases, and the reading accuracy decreases as the illuminance on the document surface decreases. Therefore, recently, the OA equipment tends to increase the document feed speed in order to increase the processing capacity and increase the efficiency of the paperwork, so that the amount of light emitted from the rare gas discharge lamp is further increased. It is desired to increase.
[0005]
In this rare gas discharge lamp, light emitted from the light emitting layer B is emitted to the outside through the aperture portion Ba and the first opening PA, and is emitted to the outside from the second opening PB. The light used for reading by the document irradiation device is only emitted to the outside through the former aperture portion Ba and the first opening portion PA. For example, in a rare gas discharge lamp in which outer electrodes C and D are arranged on the outer peripheral surface of an envelope A having an outer diameter of 6 mm and a length of 280 mm, the illuminance at the front surface 8 mm of the central portion of the first opening PA is Approximately 10000 Lx is obtained.
[0006]
However, as described above, when it is necessary to further increase the front illuminance of the first opening PA of the rare gas discharge lamp, for example, the outer diameter of the envelope A is increased, or the tube input (external electrode) Although the method of increasing the power supplied between them is employed, each has the following problems.
[0007]
That is, the former method is expected to be difficult to incorporate because the storage space for the rare gas discharge lamp is becoming narrower with the miniaturization of OA equipment. In the latter method, when the tube input is increased, the front light intensity of the first opening PA increases, but the amount of light emitted from the second opening PB also increases. Therefore, there is a problem that not only the increase rate of the amount of light emitted from the first opening PA is small for increasing the tube input, but also the lighting device is enlarged.
[0008]
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a rare gas discharge lamp that can effectively use light diffused from the second opening with a simple configuration and can increase the front illuminance of the first opening. There is.
[0009]
[Means for Solving the Problems]
Therefore, in order to achieve the above-mentioned object, the present invention provides a straight tubular envelope having a light emitting layer on the inner surface, A pair of strip-shaped external electrodes made of a metal member is formed on one surface of a translucent sheet having a length substantially the same as the entire length of the envelope so that the first and second openings are formed. A sheet structure that is spaced apart from each other, and the sheet structure is wound around the outer peripheral surface of the envelope so that an external electrode is positioned between the envelope and the translucent sheet A reflective member having light reflectivity and insulation is disposed in a portion corresponding to the second opening between the external electrodes on the outer peripheral surface of the envelope, and light is emitted from the first opening. like It is characterized by comprising.
[0010]
In addition, the first of the present invention 2 According to the present invention, a pair of strip-shaped external parts made of a metal member on one surface of a straight tubular envelope having a light emitting layer on the inner surface and a translucent sheet having a length substantially the same as the entire length of the envelope. The electrodes are spaced apart from each other so that the first and second openings are formed. And a sheet structure in which an adhesive layer having an adhesive or adhesive function is formed on one surface of the translucent sheet, the sheet structure on the outer peripheral surface of the envelope, and the envelope and the translucent The outer electrode is wound and bonded so as to be positioned between the sheet and the sheet, and the portion corresponding to the second opening between the outer electrodes on the outer peripheral surface of the envelope has light reflectivity and insulation. A reflective member having A feature is that light is emitted from the first opening.
[0011]
Furthermore, the present invention 3 According to the invention, the reflecting member is integrated with a translucent sheet portion corresponding to the second opening, and the fourth invention is provided in the first opening between the external electrodes. An aperture portion where no light emitting layer is formed is formed on the inner surface portion of the corresponding envelope.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, a first embodiment of the present invention will be described with reference to FIGS. In the figure, reference numeral 1 denotes a straight tubular envelope sealed with, for example, a glass bulb, and a light emitting layer 2 made of a phosphor such as a rare earth phosphor or a halophosphate phosphor is formed on the inner surface thereof. Although formed, an aperture portion 2a where the light emitting layer 2 is not formed is formed in a part thereof. The envelope 1 is constructed by sealing disc-shaped sealing glasses 1a and 1b at the end of a glass bulb. For example, the envelope 1 may be constructed by reducing the diameter of the glass bulb while heating it and fusing it. it can. The enclosed space of the envelope 1 contains a single or mixed rare gas such as xenon (Xe), krypton (Kr), neon (Ne), helium (He) that does not contain metal vapor such as mercury. However, it is desirable to enclose a rare gas mainly composed of xenon at a pressure of 20 to 110 Torr, for example.
[0013]
The sheet structure 3 is wound around the outer peripheral surface of the envelope 1 so as to be in close contact therewith. The sheet structure 3 has, for example, an insulating translucent sheet 4 having a length substantially equal to the entire length of the envelope 1 and a thickness set in a range of 20 to 100 μm. The non-transparent sheet 4 is bonded to the light-transmitting sheet 4 with a predetermined distance from each other so that first and second openings (8A, 8B), which will be described later, are formed on one surface. A pair of band-shaped external electrodes 5 and 6 made of a translucent metal member, terminals 51 and 61 led out from the end portions of the external electrodes 5 and 6, and a later-described formed between the external electrodes 5 and 6. Common to the reflective member 7 having light reflectivity and excellent insulating properties disposed in the portion corresponding to the second opening (8B), the translucent sheet 4, the external electrode, and the reflective member 7. It is comprised from the adhesion layer 9 which has the adhesion | attachment thru | or adhesion | attachment function provided to one surface to do.
[0014]
In this sheet structure 3, the translucent sheet 4 is preferably, for example, a polyethylene terephthalate (PET) resin. If the translucent sheet is excellent in translucency and electrical insulation, a polyester resin, a fluorine resin ( Other resins such as Teflon (registered trademark) can also be used. For the external electrodes 5 and 6, for example, an aluminum foil having light reflectivity is suitable, but other metals such as copper, silver, nickel, etc. can be used as long as they are excellent in conductivity and opaque. Members can also be used. In particular, when the external electrodes 5 and 6 are made of an aluminum foil, the thickness is set in the range of 10 to 50 μm when the aluminum foil is hard, and 30 to 100 μm when the aluminum foil is soft. It is desirable. Terminals 51 and 61 are electrically and mechanically connected to end portions of the external electrodes 5 and 6 by conductive adhesive, caulking, welding, or the like. The reflecting member 7 is made of, for example, titanium oxide (TiO ₂ ), A powder having reflectivity such as magnesium oxide (MgO), a sheet in which a reflective material such as titanium oxide or magnesium oxide is coated on an insulating sheet, foamed PET, etc. The light-transmitting sheet portion corresponding to the two openings (8B) is applied by spraying, coating, or the like, or a band-shaped member is disposed and bonded. Further, a silicone adhesive is suitable for the adhesive layer 9, but an acrylic adhesive, an epoxy adhesive, or the like can also be used. The thickness of the adhesive layer 9 is preferably about 20 to 40 μm, for example, but can be set outside this range.
[0015]
The above-described sheet structure 3 is mounted on the outer peripheral surface of the envelope 1 so that the external electrodes 5 and 6 are positioned between the envelope 1 and the translucent sheet 4. In the second opening (8B), the other end 4b is superposed on and bonded to one end 4a of the translucent sheet 4, and then welded by ultrasonic welding, thermocompression bonding, or the like. The welded portion is formed continuously or partially along the longitudinal direction of the overlapped portion, but the welding can be omitted simply by bonding. In particular, when the seat structure 3 is attached to the envelope 1, the first opening 8 </ b> A is formed between the one ends 5 a and 6 a of the external electrodes 5 and 6, and the other ends 5 b and 6 of the external electrodes 5 and 6. A second opening 8B is formed between 6b, and a reflecting member 7 is disposed in the second opening 8B. Light from the light emitting layer 2 is emitted to the outside only through the first opening 8A through the aperture 2a. The opening angle θ of the first and second openings 8A and 8B ₁ , Θ ₂ Is θ ₁ > Θ ₂ However, depending on the application, it may be set to the same or opposite relationship.
[0016]
Prior to manufacturing the rare gas discharge lamp, a sheet assembly 3A including the sheet structure 3 is prepared. The sheet assembly 3A is assembled as shown in FIGS. First, as shown in FIG. 5A, for example, a long separator 3S having a releasing function on one surface is placed on an assembly stage (not shown) and, for example, a separator is placed on one surface. -A conductive sheet 5S made of a long metal member (for example, an aluminum foil) having a width narrower than that of the cover 3S and having an adhesive layer on one surface is sequentially laminated and bonded. The separator 3S is preferably a PET resin having a thickness of about 70 μm, for example, but the material and thickness can be changed as appropriate. In particular, it is desirable to superimpose the separator 3S and the conductive sheet 5S by using a roller or the like while continuously supplying the separator 3S and the conductive sheet 5S from separate rolls. Then, separation portions 5Sa are sequentially formed so that the strip-like external electrodes 5 and 6 are formed on the conductive sheet 5S by a cutter (not shown). It should be noted that the separation portion 5Sa is designed so that only the conductive sheet 5S is cut and no break is generated in the separator 3S. Then, when the portions 5Sb and 5Sc unnecessary as external electrodes are sequentially separated (separated) from the separator 3S through the separating portion 5Sa, as shown in FIG. The external electrodes 5 and 6 forming the above are sequentially arranged at a predetermined interval.
[0017]
Next, as shown in FIG. 6A, a strip-shaped reflecting member 7 having an adhesive layer on one surface is disposed and bonded to the separator 3S adjacent to the external electrode 5. The reflecting member 7 can also be arranged by a method similar to the method of forming the external electrodes 5 and 6. Next, one ends of the terminals 51 and 61 are sequentially superposed on the end portions of the external electrodes 5 and 6 and are electrically and mechanically connected, for example, with a conductive adhesive (not shown). For example, an acrylic conductive adhesive containing nickel powder is suitable as the conductive adhesive, but an acrylic or other resin matrix containing metal powder other than nickel may be used. Next, as shown in FIG. 2B, a long translucent sheet (for example, PET) having a width wider than the entire length of the external electrodes 5 and 6 and the reflecting member 7 and having an adhesive layer 9 on one surface. Resin) 4S is adhered to one surface of the separator 3S in such a manner that the external electrodes 5, 6 and the reflection member 7 are completely overlapped with each other. The translucent sheet 4S may be wound around a roll in advance and continuously supplied to be superposed on the separator 3S. Next, the separating portion 4Sc is formed in the translucent sheet 4S at a constant interval (between a pair of external electrodes) by a cutter (not shown). Note that only the translucent sheet 4S is cut off in the separation portion 4Sc, and consideration is given to avoiding a break in the separator 3S. A long spacer (3M) having flexibility or elasticity such as a sponge and narrower than the translucent sheet 4S is overlapped on the separator 3S and not shown. The sheet assembly 3A is assembled by winding it on a roll. The spacer 3M is used when the sheet assembly 3A is in a bamboo shoot shape (a state in which the winding diameters at both ends in the width direction are different) when wound, but in particular, the sheet assembly. When 3A is wound, it is wound to substantially the same diameter over the entire width direction, and can be omitted if the form does not collapse.
[0018]
A rare gas discharge lamp is manufactured as shown in FIGS. 7 to 9, for example, using the sheet assembly 3A configured as described above. The manufacturing apparatus includes, for example, a separation apparatus 100 that separates the sheet structure 3 from the sheet assembly 3A, a transfer apparatus 200 that receives the separated sheet structure 3 and transfers it in a certain direction, and a transfer apparatus. The sheet structure 3 supplied from 200 is constituted by a winding device 300 for winding the sheet structure 3 around the outer peripheral surface of the envelope 1.
[0019]
First, as shown in FIGS. 7 to 8, the sheet assembly 3 </ b> A is disposed on the roll 101 of the separating apparatus 100. The sheet assembly 3A is set so as to be transferred to the scraper 104 via the buffer 103 so that the spacer 3M is wound around the roll 102. In particular, the scraper 104 is formed with a sharp turn portion of about 10 °, for example, and the separator 3S is wound around the roll 105 with a certain tension applied along the turn portion. When the sheet assembly 3A is sent in the direction of the arrow shown in FIG. 1, and the sheet assembly 3 is positioned below the scraper 104, the separation stage 201 of the transfer device 200 is disposed below the sheet assembly 3A. At the same time, the stage 201 is brought close to or in close contact with the sheet structure 3 and is vacuum-sucked. The stage 201 moves in the direction of the arrow shown in the figure almost in synchronization with the movement of the sheet assembly 3A. The stage 201 is fixed to the slider 202 and is configured to be movable along the rail 203. When the separator 3S is folded at an acute angle at the tip 104a of the scraper 104, the sheet structure 3 is handled at the same portion and begins to be separated from the separator 3S. Eventually, the sheet structure 3 is completely separated in relation to the movement of the separator 3S and the stage 201, and is moved to the stage 201 and transferred to a predetermined position as shown by a dotted line in the figure. In addition, since the separating portions 4Sc are formed at appropriate intervals in the translucent sheet 4S in the sheet structure, they are surely separated by handling at the tip 104a of the scraper 104. When the separated sheet structure 3 is supplied to the winding device 300, the stage 201 returns to the solid line position in FIG. The vacuum suction mechanism of the stage 201 can be omitted.
[0020]
Next, as shown in FIG. 9, the sheet structure 3 placed on the stage 301 of the winding device 300 is vacuum-sucked on the stage 301, for example, and is not shown in the X and Y axes. It is adjusted to a predetermined position by a directional position adjusting device (XY table). The envelope 1 is at the end of the reflecting member 7 (one end 4a of the translucent sheet 4) in the sheet structure 3, and the longitudinal direction thereof is the length of the reflecting member 7 (external electrodes 5 and 6). Supply / arrange along the direction (in parallel). In this state, the pair of rollers 302 and 302 that rotate freely and can move up and down are positioned so as to be elastically pressed against the upper portion of the envelope 1. In this state, the stage 301 is moved in the arrow direction M by a drive mechanism (not shown). Then, the envelope 1 rotates counterclockwise while being pressed against the rollers 302 and 302, and the rollers 302 and 302 are also rotated in accordance with the rotation of the envelope 1. Thereby, the reflecting member 7 (one end 4a of the translucent sheet 4) is adhered to a part of the outer peripheral surface of the envelope 1 in a close contact state. After that, when the stage 301 is moved in the arrow direction N, the envelope 1 rotates clockwise while being elastically pressed against the rollers 302, 302, and the rollers 302, 302 are also moved. It rotates following the rotation of the envelope 1. At this time, the translucent sheet 4 of the sheet structure 3 starts to be wound around the outer peripheral surface in accordance with the rotation of the envelope 1, starting from the one end 4a already bonded to the envelope 1. . Then, when the envelope 1 rotates, for example, about 390 ° (approximately one rotation), a translucent sheet 4 is wound around the outer peripheral surface of the envelope 1 as shown in FIG. The other end 4 b is overlapped with the one end 4 a and bonded by the adhesive layer 9. The external electrodes 5 and 6 and the reflecting member 7 are bonded to the outer peripheral surface of the envelope 1 through the adhesive layer 9. Further, if the vacuum suction force of the stage 301 is set to such an extent that it can be easily detached by winding / adhering the translucent sheet 4 to the envelope 1 by the rotation of the envelope 1, It is possible to omit adsorption stop (open) and adjustment of adsorption force during the process.
[0021]
According to this embodiment, since the reflecting member 7 is disposed in the second opening 8B formed between the end portions 5b and 6b of the external electrodes 5 and 6, the light emitted from the light emitting layer 2 is The light is reflected by the external electrodes 5 and 6 and the reflecting member 7, is densified, and is emitted from the first opening 8 </ b> A to the outside through the aperture portion 2 a. Therefore, the front illuminance of the first opening 8A can be greatly increased.
[0022]
In particular, since the reflecting member 7 is disposed in the second opening 8B, light is not emitted to the outside from the second opening 8B. For this reason, the light emitted from the second opening 8B is concentrated in the first opening 8A, and the amount of light from the first opening 8A increases, which is applied to the document irradiation apparatus. The document surface illuminance can be further increased, and the document reading accuracy can be improved even if the document feeding speed is increased.
[0023]
Further, since the reflecting member 7 is disposed at the light-transmitting sheet portion corresponding to the second opening 8B when the sheet structure 3 is manufactured, the work efficiency can be improved and the mass productivity can be improved. .
[0024]
FIG. 10 shows a second embodiment of the present invention, and the basic configuration is the same as that of the rare gas discharge lamp shown in FIGS. The difference is that the opening angle θ of the aperture 2a corresponding to the first opening 8A is different. ₃ Is the opening angle θ of the first opening 8A. ₁ The light transmitting layer 2 is set to be larger and the light emitting layer 2 does not protrude into the first opening 8A, and the sheet structure 3 is wound or closely attached to the envelope 1. -The main overlapping portion of the end portion 4b of the G 4 is set on the outer surface side of the external electrode 5, and this portion is ultrasonically welded. Note that the overlapping / welding portion may be on the outer surface side of the external electrode 6. The aperture angle θ of the aperture 2a ₃ Is set in the range of 70 to 110 degrees, for example, but can be changed as appropriate according to the application and purpose.
[0025]
According to this embodiment, the light emitted from the light emitting layer 2 is densified in the envelope and is emitted to the outside from the aperture 2a through the first opening 8A. When applied to the apparatus, the illuminance of the original surface can be increased, and the reading accuracy of the original can be improved.
[0026]
In particular, if light reflectivity is imparted to the envelope-side surface of the external electrodes 5 and 6, the front illuminance of the first opening 8A can be increased in combination with the light reflectivity of the reflective member 7, Document reading accuracy can also be improved.
[0027]
Also, the aperture angle θ of the aperture 2a ₃ Is the opening angle θ of the first opening 8A ₁ Since the light emitting layer 2 is configured not to protrude into the first opening 8A, the positional relationship between the external electrodes 5 and 6 with respect to the aperture 2a is slightly increased during manufacturing. Even if they deviate, the fluctuation of the optical axis can be stopped within a range that does not cause any practical problems. Therefore, the incorporation into the OA device becomes easy.
[0028]
Furthermore, since the ultrasonic welding of the overlapping portion of the translucent sheet 4 is performed on the outer surface side of the external electrode 5, the ultrasonic vibration acting on the light emitting layer 2 on the inner surface of the envelope is reduced. Therefore, as compared with the first embodiment, peeling of the light emitting layer 2 from the inner surface of the envelope can be significantly suppressed, and the light output can be improved.
[0029]
FIG. 11 shows a third embodiment of the present invention, and the basic configuration is the same as that of the rare gas discharge lamp shown in FIG. The difference is that the pair of strip-like external electrodes 5 and 6 are attached to the outer peripheral surface of the envelope 1 so as to face each other, and the envelope 1 corresponding to the second opening 8B of the external electrodes 5 and 6. A belt-like reflecting member 7 is attached to the outer peripheral surface of the envelope 1 and the outer peripheral surface of the envelope 1 is covered with a protective tube 10 made of a heat-shrinkable resin such as PET resin. The protective tube 10 is in close contact with the sheet structure 3 by being attached to the envelope 1 and then heated to, for example, about 150 to 200 ° C. and contracted. The protective tube 10 can be put on the sheet structure 3 in the first and second embodiments. In this case, even if the application conditions of the rare gas discharge lamp are severe, such as severe environmental conditions and high safety standards, higher quality products can be provided.
[0030]
According to this embodiment, similarly to each of the above-described embodiments, the front illuminance of the first opening 8A can be effectively increased, and the translucent sheet 4 can be used as in the above-described embodiment. Since there is no need to overlap the end portions 4a and 4b, there is no inconvenience that the overlapping portion peels off during use.
[0031]
In particular, prior to mounting the protective tube 10 on the outer peripheral surface of the envelope 1, if an insulating film such as a silicone varnish is formed on the outer peripheral surface of the envelope 1 in advance, This can improve the insulation and suppress the occurrence of creeping discharge.
[0032]
FIG. 12 shows a fourth embodiment of the present invention, and the basic configuration is the same as that of the rare gas discharge lamp shown in FIG. The difference is that both end portions of the belt-like reflecting member 7 are extended and overlapped with the end portions 5 b and 6 b of the external electrodes 5 and 6. According to this configuration, since no gap is formed between the end portions 5b and 6b of the external electrodes 5 and 6 and the reflecting member 7 in the second opening 8B, light reflection at the opening (8B) is performed. It becomes possible to further improve the sex.
[0033]
The present invention is not limited to the above-described embodiments. For example, for providing light reflectivity to a portion corresponding to the second opening, a band-shaped reflecting member is disposed, or a reflecting material is applied. In addition to spraying, a reflective material can be directly applied to the envelope itself, or the insulating member can be made reflective. The external electrode is disposed substantially over the entire length of the envelope. The meaning of “substantially full length” includes up to about 20% reduction in the total length of the envelope.
[0034]
【Example】
Next, a first experimental example will be described. The sheet structure shown in FIGS. 3 to 4 is wound and brought into close contact with an envelope made of lead glass having an outer diameter of 8 mm and a length of 300 mm. The outer electrode in this sheet structure is made of strip-shaped aluminum having a thickness of 70 μm and a width of 8 mm, and a light-transmitting sheet portion corresponding to the second opening (width is 3 mm) is provided on Toray Industries, Inc. Further, E60L (reflective member) sold as foamed PET is processed into a belt shape and attached, and an adhesive layer having a thickness of 35 μm is formed on the entire surface of the translucent sheet.
[0035]
A high frequency high voltage of 25 KHz and 2500 Vo-p was applied to the external electrode of this rare gas discharge lamp, and the illuminance at the front 8 mm point in the center of the first opening was measured. The illuminance increased by 28% compared to the conventional noble gas discharge lamp.
[0036]
Next, a second experimental example will be described. The sheet structure shown in FIGS. 3 to 4 is wound and brought into close contact with an envelope made of lead glass having an outer diameter of 8 mm and a length of 300 mm. The outer electrode in this sheet structure is a strip-like aluminum having a thickness of 60 μm and a width of 8 mm, and the thickness of the light-transmitting sheet portion corresponding to the second opening (width is 3 mm). A reflective film of magnesium oxide having a thickness of approximately 40 μm is formed, and an adhesive layer having a thickness of 35 μm is formed on the entire surface of the translucent sheet.
[0037]
When a high frequency high voltage of 25 KHz and 2500 Vo-p was applied to the external electrode of this rare gas discharge lamp and the illuminance at the front 8 mm point in the center of the first opening was measured, a magnesium oxide film with the same size was formed. The illuminance increased by 35% compared to the conventional noble gas discharge lamp.
[0038]
【The invention's effect】
As described above, according to the present invention, the light emitted from the light emitting layer is provided because the portion corresponding to the second opening formed between the end portions of the external electrode is provided with light reflectivity. Are not discharged from the second opening to the outside, but almost all are collected in the first opening. Therefore, the amount of light emitted from the first opening can be increased, and the front illuminance can be effectively increased.
[0039]
In particular, if an aperture portion in which the light emitting layer is not formed is formed in the light emitting layer, the light emitted from the light emitting layer is densified on the inner surface of the envelope, and the first opening portion is passed through the aperture portion. Since it is emitted from the outside, the front illuminance of the first opening can be further increased.
[0040]
And ,this For document illumination When the rare gas discharge lamp is applied to the document irradiation device, the illuminance on the document surface can be effectively increased. Therefore, even if the document feed speed is increased, the document reading accuracy can be improved. .
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line XX in FIG.
FIG. 3 is a development view of a sheet structure according to the present invention.
4 is a YY sectional view of FIG. 3;
FIG. 5 is a view for explaining a method for manufacturing a sheet assembly according to the present invention, in which FIG. 5 (a) is a plan view showing a state in which a conductive sheet is superimposed on a separator. FIG. 5B is a plan view showing a state in which an unnecessary portion of the conductive sheet is removed and an external electrode is formed.
FIG. 6 is a view for explaining a method for manufacturing a sheet assembly according to the present invention, in which FIG. 6 (a) is a plan view showing a state in which a reflecting member is arranged and terminals are connected to external electrodes. The figure and the figure (b) are the top views which show the state which piled up the translucent sheet | seat on the separator.
FIG. 7 is a schematic side view of a manufacturing apparatus according to the present invention.
8 is an enlarged cross-sectional view of a main part of the manufacturing apparatus shown in FIG.
FIG. 9 is a cross-sectional view for explaining a method of winding the sheet structure around the envelope according to the present invention.
FIG. 10 is a longitudinal sectional view showing a second embodiment of the present invention.
FIG. 11 is a longitudinal sectional view showing a third embodiment of the present invention.
FIG. 12 is a longitudinal sectional view showing a fourth embodiment of the present invention.
FIG. 13 is a longitudinal sectional view of a conventional example.
[Explanation of symbols]
1 Envelope
2 Light emitting layer
2a Aperture part
3A sheet assembly
3S long separator
3 Sheet structure
4S long translucent sheet
4 Translucent sheet
4a, 4b end
4Sc separation part
5S long conductive sheet
5,6 External electrode
51, 61 terminals
7 Reflective members
8A First opening
8B Second opening
9 Adhesive layer
10 Protection tube (insulating member)
100 Separator
104 Scraper
200 Transfer device
201, 301 stage
300 winding device
302 Roller

Claims

A straight tubular envelope having a light emitting layer on the inner surface, and a pair of strip-shaped external electrodes made of a metal member on one surface of a translucent sheet having a length substantially the same as the entire length of the envelope, 1 and a sheet structure formed so as to be spaced apart from each other so that a second opening is formed,
The sheet structure is wound around the outer peripheral surface of the envelope so that the external electrode is positioned between the envelope and the translucent sheet,
A reflective member having light reflectivity and insulation is disposed in a portion corresponding to the second opening between the external electrodes on the outer peripheral surface of the envelope ,
A rare gas discharge lamp for illuminating a document , characterized in that light is emitted from a first opening.

A straight tubular envelope having a light emitting layer on the inner surface, and a pair of strip-shaped external electrodes made of a metal member on one surface of a translucent sheet having a length substantially the same as the entire length of the envelope, 1 and a sheet structure which is arranged so as to be spaced apart from each other so as to form a second opening, and has an adhesive layer having an adhesive or adhesive function formed on one surface of the translucent sheet. ,
The sheet structure is wound and bonded to the outer peripheral surface of the envelope so that the external electrode is positioned between the envelope and the translucent sheet,
A reflective member having light reflectivity and insulation is disposed in a portion corresponding to the second opening between the external electrodes on the outer peripheral surface of the envelope ,
A rare gas discharge lamp for illuminating a document , characterized in that light is emitted from a first opening.

3. The rare gas discharge lamp for illuminating a document according to claim 1, wherein the reflecting member is integrated with a translucent sheet portion corresponding to the second opening.

3. A rare gas discharge lamp for illuminating a document according to claim 1, wherein an aperture portion where no light emitting layer is formed is formed on an inner surface portion of the envelope corresponding to the first opening between the external electrodes.